MLB matchup analysis
Mariners vs Red Sox Prediction, Odds and Model Pick
Tuesday, September 1, 2026 at Fenway Park · 6:45 PM ET
LyDia decision: Pass on Mariners vs Red Sox
The case for Seattle Mariners
The case for Boston Red Sox
Why it is not official
Why the setup score is what it is
Why the price is what it is
Read the full model output
This is a bullpen game -- no confirmed traditional starter, so LyDia does not publish an official pick here.
Final result
Mariners 9, Red Sox 6
How the analysis held up
Seattle Mariners won, the side LyDia's model favored.
LyDia's two internal reads disagreed pregame by 64.3 points — the team-strength model favored Seattle Mariners, the run-projection model favored Boston Red Sox. The team-strength model had the winner here.
Bryan Woo (Seattle Mariners), the starter LyDia's pitcher score favored, actually outpitched Jedixson Paez: 6.0 IP, 1 ER (1.50 ERA) against 3.2 IP, 8 ER (19.64 ERA). The edge held up.
The Seattle Mariners bullpen was flagged as elevated risk pregame (Tired). In relief it actually allowed 4 earned runs over 3.0 innings (12.00 ERA) — the risk read showed up. Note: 1 of the runs charged to the Seattle Mariners pitching staff overall was unearned — not something the bullpen's stuff should be blamed for.
The Boston Red Sox bullpen was flagged as elevated risk pregame (High risk). In relief it actually allowed 1 earned run over 5.1 innings (1.69 ERA) — the risk read did not show up on the scoreboard tonight.
Seattle Mariners scored 9, 5.3 more than the 3.7 pregame projection.
Game information
| Matchup | Seattle Mariners at Boston Red Sox |
|---|---|
| Date | Tuesday, September 1, 2026 |
| First pitch | 6:45 PM ET |
| Venue | Fenway Park |
| Starting pitchers | Bryan Woo vs Jedixson Paez |
| Weather | Game-time forecast: 64°F, 2% precipitation chance, 1 mph wind from NW. |
Starting pitcher matchup
Full Pitcher Matchup Tool →| Metric | Mariners | Red Sox |
|---|---|---|
| Pitching plan | Traditional starter | Opener / bullpen game |
| Expected innings | 5⅔ | 3 |
| Throws | R | R |
| LyDia pitcher score (higher is better) | 68 | 23 |
| ERA (lower is better) | 4.29 | 18.90 |
| WHIP (lower is better) | 1.10 | 2.85 |
| K/9 (higher is better) | 9.0 | 4.0 |
| K-BB% (higher is better) | 19.3% | -5.1% |
| K% (higher is better) | 24.5% | 7.7% |
| BB% (lower is better) | 5.2% | 12.8% |
| BB/9 (lower is better) | 1.9 | 6.8 |
| HR/9 (lower is better) | 1.1 | 5.4 |
| Ground-ball rate | 40.4% | 52.9% |
| Fly-ball rate | 59.6% | 47.1% |
Pitching plan edge: LyDia gives Bryan Woo the edge over the Boston Red Sox pitching plan (4 points on LyDia's pitcher score). Jedixson Paez is projected for only 3 innings, with the Boston Red Sox bullpen covering the rest -- this compares Bryan Woo's own line against the Boston Red Sox blended starting-pitcher-and-bullpen quality, not two starters directly.
Blended read: For the Boston Red Sox, the bullpen is projected to throw more of the game than Jedixson Paez (about 3 innings for the starter), so LyDia grades that side on a whole-game effective ERA of 4.23 rather than Jedixson Paez's own 18.90. Whole-game, that is 4.23 for the Boston Red Sox against 5.17 on the other side, so the blended read leans Boston Red Sox.
How to read this: the scorecards above name the starters; every number lives in this table.
Strikeout Projections Full strikeout projections →
Same data source as the Pitcher Matchup Tool, where every starter on the slate is compared side by side.
Recent form
Full Stats page →Mariners are 4-6 in their last 10 and averaging 3.8 runs per game over the last 15 days; Red Sox are 6-4 in their last 10 and averaging 4.9 runs per game over the last 15 days. On the season Red Sox carry the better run differential per game (+0.59 against -0.50).
| Metric | Mariners | Red Sox |
|---|---|---|
| Last 10 | 4-6 | 6-4 |
| Last 10 by venue (away team on the road, home team at home) | 4-6 on the road | 6-4 at home |
| OPS, last 15 days | 0.625 | 0.791 |
| wOBA, last 15 days (hot/cold read) | 0.283 | 0.347 |
| Runs per game, last 15 days | 3.8 | 4.9 |
| K% last 15 days (lower is better) | 27.1% | 16.8% |
Last 15 days only. Hot and cold streaks for all 30 teams live on the Stats page.
30-day offense
Full offense tool →| Last 30 days | Mariners | Red Sox |
|---|---|---|
| OPS | 0.676 (-0.009 vs szn) | 0.800 (+0.072 vs szn) |
| Runs per game | 3.70 (-0.232 vs szn) | 5.45 (+0.959 vs szn) |
| wOBA (model offense input) | 0.302 | 0.349 (+0.028 vs szn) |
| K% (lower is better) | 24.4% (+1.1% vs szn) | 18.6% (-2.6% vs szn) |
Over the last 30 days the Red Sox have been the better offense, 0.349 wOBA to 0.302. They are running hot against their own season line (+0.028 wOBA). Mariners are striking out at 24.4% over the window — something the opposing starter can lean on.
Season profile
Full Stats page →| Metric | Mariners | Red Sox |
|---|---|---|
| Record | 64-74 | 75-63 |
| Run differential / game (team quality) | -0.50 | +0.59 |
| Runs scored / game (offense, season) | 3.94 | 4.49 |
| Runs allowed / game (defense, season, lower better) | 4.44 | 3.90 |
| Season OPS | 0.682 | 0.728 |
| K% season (lower is better) | 23.3% | 21.3% |
| OPS vs opposing hand (season) | 0.701 | 0.715 |
Season-long team quality, not recent form. Run differential and run environment come from the season standings; splits for all 30 teams live on the Stats page, including the run environment table.
The Map
Full interactive map →Every team on today's slate, on any two axes you pick. Mariners and Red Sox are highlighted.
Bullpen matchup
Full Bullpen Fatigue Index →Risk is what the model actually uses: fatigue blended with how well the pen has pitched. High fatigue with high efficiency is a tired pen that is still getting outs.
| Metric | Mariners | Red Sox |
|---|---|---|
| Fatigue | 7.2/10, Tired | 7.4/10, Tired |
| Efficiency | 3.8/10, Below average | 2.9/10, Struggling |
| Combined risk | 7.8/10, Tired | 8.5/10, High risk |
| Relief innings, last 7 days | 20.3 | 29.3 |
| Back-to-back arms | 4 | 5 |
| 7-day ERA | 5.31 | 7.06 |
| 7-day WHIP | 1.62 | 1.53 |
Fatigue measures workload. Efficiency measures recent run prevention. Combined risk is what the moneyline and totals systems use.
Run total projection
Full Totals Projections →The model projects 1.6 runs above the market total. A research lean still requires a setup rating of at least 7.0/10. Team totals remain research-only until their graded sample is established.
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